what bar boost?

[craig l]

hi ive got a jspec 6sp tt what boost should i be running its got a blitz nur spec double decat restrictor ring hks induction thor fcd walbro fuel pump ngk laser platinum plugs sard bov. ive got a crappy raid boost gauge that flutters about 0.8 0.9 bar is this normal should it not be over a bar, what is standard boost cheers

[Homer]

It is 0.76 bar stock, with the cats removed and no restrictor ring the boost overuns to 1.6bar plus. The idea with Jspecs is to fit a restrictor rings that will bring this down to your taregt boost (normally between 1 and 1.2bar).

You do not need a boost controller to acheive this. Try removing the boost controller and seeing what pressure you're getting, then work from there :)

[Jake]

You do not need a boost controller to acheive this. Try removing the boost controller and seeing what pressure you're getting, then work from there :) I don't think he mentioned a boost controller?

[Homer]

I don't think he mentioned a boost controller?

lol, ooops. Got mixed up with another thread! In that case ignore the bit above about the boost controller :rolleyes:


If its only reaching 0.8-0.9 bar then it could be one of a few things:

1) Restrictor ring is too restrictive
2) Boost gauge is reporting wrong pressure
3) wastegate/VSV fault maybe..

[craig l]

thanks guys ye dont have a bc yet prob my next purchase the restrictor rings from chris wilson its a 1.1bar the boost gauge is a cheap raid one so might be that it doesnt go past a bar though it flickers round about the 0.8 0.9bar so what bar should it be with the mods

[hadyn]

I used to make about 0.95-1bar on a tt jspec auto with both cats out and 1.2 bar restrictor ring. Every car is different

[craig l]

was expecting a bit more than standard with the mods i thought with it being a 1.1bar ring thats what it would boost to. i still dont know a lot about the car yet can someone explain what the problem would be if it was the wastegate cheers

[hadyn]

what condition is your intercooler in?

[Homer]

I'd get a decent boost gauge before trying the other (potentially more expensive) options. You can get a half-decent electronic one for around £80.

[craig l]

not a clue mate never looked at it yet lol its a 95m when do they usually need replacing its only done 61000

[Rayman]

Yeh ive just fitted new smic and get 0.9boost with just exhaust fitted, not sure how accurate my boost guage is tho. Its one of those blitz turbo timer ones!

[Rayman]

not a clue mate never looked at it yet lol its a 95m when do they usually need replacing its only done 61000

Yeh if it crumbles when you touch it its knackered!

[hadyn]

stock intercoolers can become very flakey and inefficient, see this thread for the state of mine that came off:

http://mkivsupra.net/vbb/showthread.php?t=93169&highlight=miami

[craig l]

thanks for the help guys ill have a look at the smic was thinking about replacing it soon anyway or going for a fmic cheers

[Homer]

thanks for the help guys ill have a look at the smic was thinking about replacing it soon anyway or going for a fmic cheers

A new SMIC will only raise your boost if it has a hole in it (very unlikely)

Check for boost leaks, get a decent boost gauge and go from there.